Hominin tool-making: laterality, language, and learning

The origins of language can be addressed through the proxy of right-handedness, which in humans occurs in about 90% of the species. Homo sapiens have the strongest lateral bias seen in any great ape. In order to trace the emergence and evolution of right-handedness, it is vital to obtain laterality data from hominins since the last common ancestor. One useful source of data is prehistoric stone tools, specifically traces of lateralised production and use.

This paper presents a critical analysis of several methods of identifying right-handedness in stone tools, using a combination of biomechanics, archaeological experiments, ethnographic parallels, and lithic analysis. Single-platform core rotation was not found to be validated, nor was the "coup de tranchet" knapping technique. The most robust archaeological evidence for prehistoric handedness was found in the lateralised resharpening of scrapers, which yield a 79% right-handed preference among the Neanderthal knappers at the site of La Cotte de St. Brelade, Jersey.

The results of this study show that Neanderthals are currently the earliest hominin species to show reliable evidence for species-level right-handedness. With this modern laterality indicating a proxy for linguistic ability, pre-modern Europeans can be considered quite modern in their language and cognition.

The author wishes to thank the British Academy "Lucy to Language" Project and the Leverhulme Trust Early Career Fellowship for their support.